Method of producing carbon black from mixtures of acetylene and other hydrocarbons



June 12, 1923.

METHOD OF PRODUCING CARBON Illllllllllllih llllllllllll 1,673,496 L. R. CHURCHILL- BLACK FROM MIXTURES OF ACETYLENE AND OTHER HYDROCARBONS.

Filed July 11,. 1925 III . J mnuuuumnum .1 MENTOR} [km/4w A. (wee/#41.

ATT RNEY A bon black bars been from the incomplete pressure, which may be utilized in practicingity carbon black may be produced by the CO and gas mixed with air or oxygen. The pro- Patented June 12,192s. p I i UNITED. STATES PATENT OFF-ICE.

woman) a cnuncnnn, or BAYONNE, NEW .mnsny, ass'rerfon To THEGOODYEAR TIRE & RUBBER COMPANY, or AKRON, 01110, 'n conronarxon or OHIO. j

Jum'non or rnonucme cannon BLACK snbm mxxrunss I nynnocamzons.

,Application flled'luly 11, 1923. Serial mi. 650,89}.

-My invention pertains to the. production facture, use and sale thereof, to denote the of carbon black, and it has particular rela product of the incomplete combustion of tion to'the roduction of such material from natural. as. v s v mixtures o acetylene gas'and' other hydro- The single figure of the accompanying carbons, drawing is a transverse sectional View of a Heretofore, the principal source of Farcylinder adapted for confining gases under combustion of natural gas or methane, but my nvention. carbon black so produced is frequently of inferior quality, and in addition; the process of production is wasteful.

One, of the main applications of carbon xylene or" the like, either pure or i'nadmix black is found in its utilization as afiller ture, or any sufficiently volatile petroleum light; oils, as'derivedfrom the distillateof In order to be: of any great value in the .carbon and hydrogemat a somewhat ,elerubber industry,,the carbon black must necvatcd temperature. Inorder to secure a sufessarily be of high quality and, consequentfic1ent1y high temperature, the hydrocarbons ly, the inferior carbon black frequently promay be mixed with a small amount of air, duced by the incomplete combustion ofor oxygen, to burn a fraction of them to inethane is unfi'tfor compounding with rub-- er. I Y

The quality of carbon blackis manifested" will not produce satisfactory decomposition by its obscuring power and bythe size of without an excessive loss by burning. In the particles thereof, black of good quality other words, it becomeslnecessary to burn consisting of very finely divided particles. the larger portion of the hydrocarbon in" Exposing carbon black to heat for a long order to heat the remainder sufliciently to period causes its deterioration, since the par,- decompose.

plode an air-hydrocarbon mixture, such a If an attempt is made to ex l ticlgs thereof agglomerate and become hard i one 1 l a concentration of air must be utilized that It hasbeen suggested that very high qualpracticalg all of the hydrocarbon goes to detonation of acetylene gas, or ofacetylene mobile engines.

posed method was to confine -the gas, or pecially under pressure, decomposes with mixture of gases,"in a suitablechamber unextreme violence into its elements with the ,i as

Hydrocarbons, such as natural gas and coal or its components, benzene, toluene,-

in compounding with rubber in the produchydrocarbons, such as petroleum. ether, are

tion of a wide variety of rubber artlcles. capable of decomposition'into their elements form the heat necessary toraise the temperature of the remainder. j However, this alone This is demonstrated in auto derpressure and effect a detonation thereof rapid evolution of large amounts of heat.

by any suitable means, such as an electric Consequently? D the rapid decomposition or spark. The resulting extremely violent exdetonatlon o the acetylene ma be utilized 'plosion or detonation decomposed the acetyto promote the d p i ion 9 more Stable 9116 i t it l t rb d hydro en; materials associated therewith. The violence and resulted in the deposition of a very; 119,- and P y W tll Which the decomposition ly divided form of carbon black, which also Occurs epends, h WBVBI', up n he pressure,

possesses a high obscuring power. In fact, andifthe acetylene bexmixed with other hyexperimental tests have proven that carbon drocarbons and air, its detonating actionis black so produced is especially adapted for greatly decreased. This reduction in-the detcompoundin with rubber to produce high ati g action f the ac y en y its difquality pro ucts. r p fusion into the other gas, maybe obviated The term carbon blackxis herein employed by my novel method of introducin' the gases to denote the carbon deposit resulting from into an explosion chamber and t the decomposition of acetylene and other hyof ignition. For example, the air and other e manner drocarbons. This explanation of the term hydrocarbons may first be introduced into d is offered since carbon black is generally the explosion chamber, and the acetylene understood, by those engaged in the manusubsequentlyintroduced therein, when a suit.

Ol's ACETYLENE AND OTHER -Acetylene is inherently unstable, and, esa able pressure may beestablished. Immediately after the introduction of the acetylene into the explosion chamber, and before it has had time to diffuse into the rest of the gas, thus getting diluted and having its detonating action decreased, an electric spark maybe caused to ignite or detonate the almost pure acetylene remaining near the inlet opening of the chamber. Such a method effects a detonation of the, almost pure acetylene gas whereby the entire gaseous content of the chamber is subjected to an explosion of extreme violence.

Obviously, the necessity of segregating the acetylene gas from the mixture of other hydrocarbons and air might be avoided by employing a higher pressure for the whole mixture, because this would raise the pressure of the acetylene. However, this is not particularly desirable because the pressure realized upon the explosion of such a mixture is proportional to the initial pressure. It is desirable, therefore, to maintain the initial pressure as low as possible to obtain 1 the detonating result, since veryhigh presf tion into which conduits .3 and 4 are connected to provide for circulating a cooling medium, such as water, around the cylinder walls. An inlet pipe 5 isfitted within an opening located in the cylinder 1 to communicate with the interior thereof, and is provided with a suitable valve 6. -A spark plug 7, of ordinary construction, is secured within the inlet pipe 5 adjacent to the cylinder to afford means for igniting or detonating the gas which is to be decomposed.

In racticing my invention, air or oxygen may e first admitted to the cylinder 1 through the inlet pipe 5, after which a hydrocarbon, such as petroleum ether, benzene, methane, or the like, is introduced into the chamber. Acetylene is then forced into the chamber and a suitable ressure is established. The ressure estab 'shed in the explosion cham er may be varied to a great extent without sacrificing quality or percentage of yield of carbon black, but robably the lower limit of pressure shou d be substantially 15 pounds pr square inch, and the upper limit is controlled by the strength of the explosion chamber that [may be provided by known materials of construction. However, I have 'found that from 50 cant when it is considered that only a very tenths volume of methane may be mixed to 75 pounds per square inch produces very satisfactory results both in quality and quantity of production. The valve 6 in the inlet pipe is, of course, closed when a suitable pressure of the gas is established in the chamber. Immediately after the acetylene has been introduced into the chamber, a spark is caused to bridge the gap of the s ark plug by any suitable means, not s own, whereupon the acetylene gas adjacent the' inlet opening of the chamber is detonated. I

The detonation of the acetylene effects a decomposition of the other hydrocarbon introduced into the chamber, and a carbon black of very high quality is deposited in the chamber. In order to maintain the quality of the carbon black thus produced, it should be removed from the explosion chamber at frequent periodic intervals. If desired, it may be removed after each explosion, or it may be removed after a predetermined series of explosions, it only being necessary to determine how long the carbon black de osit may be left in the chamber without eterioration. The cylinder is,

' of course, constantly cooledby a circulation of Water through the conduits and around the cylinder jacket.

If petroleum ether'or other volatile petroleum hydrocarbons are utilized in admixture with acetylene, such hydrocarbons are introduced into the explosion chamber in the form of a vapor. It is desired, therefore, that the term gas, as employed in the claims, be inter reted to include the vapor form of light 011s or volatile petroleum hydrocarbons.

The importance of my invention is signifismall proportion of methane may be exploded in a mixture of acetylene gas and air at atmospheric pressure. Thehighest roportion of methane that may be utilize in a mixture of acetylene under atmospheric pressure is one-tenth volume of methane, four volumes of acetylene and one volume of "air, but if the gases are subjected to a pressure of 75 pounds per square inch, sevenwith four volumes of acetylene and one volume of air to secure a high yield of carbon black. It will be seen, therefore, that approximately seven times the quantity of methane may be utilized with acetylene to produces. high quality carbon'black when the pro er method of handling the gases is ado ted? Moreover, when the gases are confine in an explosion chamber and the'aceti ylene is utilized as a detonating a ent by explodin the acetylene before it as become di used into the other gas, a much higher proportion of the stable gas may be utilized. For exam le, five volumes of acetylene may be' a ed with five vol- 1 umes of methane and one volume of air 4 under substantially 75 pounds pressure to obtain a high yield of fine quality carbon black. My invention, therefore, materially increases the amount of cheaper hydrocarbons that may be utilized with acetylene to produce carbon black of high quality.

It will be appreciated that the hydrocarbon most suitable for use with the acetylene depends to a great extent upon the market conditions of the gases. For example, although petroleum ether is now more expensive than methane, nevertheless compared with a volumetrically equal quantity it is productive of from five to six times the carbon obtained from methane, and, inasmuch as acetylene is so expensive, the increased carbon yield on acetylene 'more, than pays the difference of petroleum ether over methane. My invention, however, is not especially directed to the particular admixture of gases utilized. but comprehends more particularly the utilization of a detonating agent to decompose a relatively stable gas into its elements to produce high quality carbon black.

Although I have specifically described a. method embodying my invention, it will be obvious that minor changes may be made therein without departing from the spirit or scope of the invention, and I desire, therefore, that no limitations shall be imposed except such as are indicated in the appended claims.

What I claim is: 1..A method of producing carbon blac which comprises introducing five volumes of hydrocarbon gas and one volume of air into an explosion chamber, introducing-a segregated charge of acetylene into the chamber,

and exploding the whole before the acetylene has been diffused through the hydrocarbon gas.

2. A method of producing carbon black which comprises introducing approximatel five volumes of hydrocarbon gas and one vo umeof air into an explosion chamber, introducing a segregated charge of acetylene into the chamber, exploding the whole be fore the acetylene has been difiused through the hydrocarbon gas, and cooling the chamber preparatory to the insertion of a new charge.

3. A method of producing carbon black that involves the continuous repetition of a cycle which comprises introducing a mix ture of air and a hydrocarbon gas into an explosion chamber, forcing a large volume of acetylene gas into the chamber, detonating the whole before the acetylene diffuses into the other gas, and cooling the chamber.

4. A method of producing carbon black that involves the continuous repetition of the following cycle: introducing a mixture of air and methane into anexplosion chamber, forcing a large volume of acetylene gas into the chamber under pressure. effecting a detonation of the whole charge by producing an electric spark in the acetylene before it is materially diffused, and cooling the chamber. A

5. A method of producing carbon black that involves thecontinuous repetition of the following cycle: introducing a mixture of air and a volatile petroleum hydrocarbon into an explosion chamber, forcing a large volume of acetylene gas into the chamber under pressure, effecting a detonation of the whole charge before the acetylene can become materially diffused by producing an electric spark'in the acetylene and cooling the chamber.

In witness whereof, I have hereunto signed my name.

LEONARD R. CHURCHILL. 

